Producing 3D rendering is now required by customer and yard as soon as possible. There are different level of 3D rendering we can produce depending on time, budget and the stage of development.
I have attached 3 kind of 3D render. The fastest to produce is a black & white sketch style, it is actually done from a rough 3D CAD model and then sketch over it in Photoshop. It is very fast as the 3D model does not need to be accurate and we don't need to spend time picking colors.
The second one is also from a 3D CAD data but with more accurate data and then Photoshop in color and with texture. This is useful for customer to select colors and material.
The last one is produce using 3D CAD rendering software. It gives photo realistic render but it is very time consuming as we need an accurate 3D model for each parts and then pick the right material texture. For exterior rendering the lightening of the model is not too difficult but for interior rendering it can takes couple of days to create the right lighting scene. However when all the model is completed it is very quick to get render from any point of view. My PC took about 45min to create this render, but you can work on other thing while the PC is processing the render.
